Fibrous crystal aggregates, preparation method thereof and use thereof

ABSTRACT

A crystal substance formed by precipitating as fibrous aggregates by making a metal aliphatic carboxylate dissolve completely in pure water, stirring, and gradually cooling the resulting solution. A method of preparing the fibrous crystal aggregates. A material for recovering flowing oil and method of recovering flowing oil by using the fibrous crystal aggregates. A material for solidifying liquid hydrocarbon, waste tempura oil and edible oil and method of solidifying liquid hydrocarbon, waste tempura oil and edible oil by using the fibrous crystal aggregates. A method of preparing the solidifying material.

FILED OF THR INVENTION

[0001] The present invention relates to fibrous crystal aggregates forefficiently adsorbing and solidifying oil flowing into rivers, lakes,marshes or the ocean; to a method of preparing the same; to the usethereof as an agent for recovering the flowing oil; and to a method ofsolidifying and recovering the flowing oil by using the recoveringmaterial.

[0002] Further, the present invention relates to a liquidhydrocarbon-solidifying material for efficiently solidifying liquidhydrocarbon, to a method of preparing the same, and to a method ofsolidifying liquid hydrocarbon by using the solidifying material.

[0003] Further, the present invention relates to a solidifying materialfor efficiently adsorbing and solidifying waste tempura oil dischargedmainly after cooking in home, production of foods, sale, and businessactivity; and to a method of solidifying and recovering waste tempuraoil by using the recovering material.

[0004] Further, the present invention relates to an edibleoil-solidifying material for efficiently solidifying edible oil, to amethod of preparing the same, and a method of solidifying edible oil byusing the solidifying material.

BACKGROUND OF THE INVENTION

[0005] As the scale of petrochemical industry is enlarging year by yearand mass production and mass consumption of organic compounds areconducted for organic compound, environmental pollution and accidentsthreatening the existence of human beings and living things, such aspollution in rivers, lakes, marshes and sea, fires and explosionsattributable to accidents in various chemical factories, petrochemicalcomplexes and tankers, occur frequently worldwide. Accordingly, safehandling of organic compounds including petrochemical materials, andsuitable handling during transportation, during storage or afteraccidents is a critical problem.

[0006] One of the fundamental measure against such pollution andaccidents is to prevent the accidents themselves by designing anapparatus capable of safe reactions, storage or transportation. The nextbest measure is to conduct suitable handling immediately after theaccidents.

[0007] When the surface of the water is polluted by an accident in achemical factory, a petrochemical complex or a tanker, one of thefollowing two methods has been used in many cases: in one method, thepollutants are left as they are until they are naturally evaporated,diluted or degraded: and in the other method, the pollutants areforcibly diluted by spraying a large amount of surfactants or the like.However, the environment is inevitably adversely affected for a long orshort period of time, so it cannot be said that both the methods aresatisfactory. In an alternative method, flowing oil is enclosed with anoil fence and scooped up together with polluted seawater by anoil-recovering ship, then the oil is separated from seawater by using adifference in density, and the seawater is returned to the sea. However,this method is poor in efficiency, resulting in permitting a majority ofthe flowing oil to spread and failing to recover it completely, thusallowing the pollutants to be left as they are.

[0008] Degradation of flowing oil by microorganisms living in seawateris also attempted, but this attempt is at the experimental stage and farfrom being practical.

[0009] In consideration of these circumstances, there is demand fordevelopment of a technique by which oil flowing into rivers, lakes,marshes or the sea is rapidly adsorbed and recovered as it is ifpossible.

[0010] The requirements for a material for adsorbing oil flowing intothe sea include: (1) the adsorbing material can act with its functionsnot deteriorated by salts in seawater, and can be easily recoveredtogether with oil, and the recovered adsorbing material is usablethrough recycling, (2) the adsorbing material is chemically relativelystable, and (3) the adsorbing material is supposed to be used in a largeamount, and should thus be a safe and nontoxic substance, and even ifthe material flows into the ocean and hardly recovered, the materialitself is least dangerous to living things in the ocean and to theenvironment.

[0011] Further, when oil flows into fresh water or hard water in rivers,lakes, marshes and the like, it is necessary that the adsorbing agent(adsorbent) can act efficiently without being influenced by the type andconcentration of ions contained in the water, thus functioning in thesame manner as in seawater.

[0012] It is hard to say that such physicochemical adsorbing materialsincluding those commercially available as gelling agents aresufficiently practically usable, since they are very poor in efficiency.

[0013] Further, one of fundamental measures against accidents such asthe above-described explosions, fires, leakage and the like, is that alarge amount of liquid hydrocarbon and mixtures thereof handled invarious chemical factories, petrochemical complexes and tankers areconverted into safe solids and returned if necessary to the originalliquid ones. By conversion thereof into safe solids easy to handle, itis thought that many accidents would be prevented, while huge and oftendangerous storage facilities, pipelines, trucking, freezing, thermallyinsulating facilities and the like could be significantly modified.

[0014] In consideration of these aspects, there is demand fordevelopment of a method wherein a wide variety of hydrocarbon and mixedoil handled in various chemical factories, petrochemical complexes andtankers are solidified and converted easily into safe forms and returnedif necessary to the original liquid hydrocarbon.

[0015] The requirements for a material for solidifying liquidhydrocarbon include (1) liquid hydrocarbon can be solidified easily atroom temperatures without damaging reaction units in a factory, and fromthe solidified complex, the original liquid hydrocarbon can be easilyrecovered, and further the recovered solidifying material is usablethrough recycling, (2) the solidifying material is chemically relativelystable, and (3) the solidifying material is supposed to be used in alarge amount, and should thus be a safe and nontoxic substance, and evenif the material flows outside of the reaction unit and hardly recovered,the material itself is least dangerous to living things in theenvironment and to the environment.

[0016] Such physicochemical adsorbing materials are still not put topractical use, and there are few proposals including those at theexperimental stage.

[0017] Besides, as our eating habits in home become rich and foodindustries become prosperous, a large amount of waste tempura oil isdischarged into sewage and the like, which raises a social problem as acause of environmental pollution.

[0018] Materials for physicochemically adsorbing waste tempura oil havebeen commercially available, but are still not satisfactory, becausetroublesome and dangerous heating for solidification is necessary, thesolidifying materials themselves have a problem in safety, and a largeamount of solidifying materials is needed in comparison with wastetempura oil.

[0019] On the other hand, a wide variety of edible oil has come to beused to enrich our life. A wide variety of edible oils which differs incharacteristics such as nutritive value, flavor, feeling in eating andthe like have been produced, but the field of application as food isrestricted and narrowed by the oils being liquid. It is estimated thatif edible oil can be solidified or gelled with maintaining theiroriginal characteristics, their value in practical use can besignificantly improved.

[0020] Such satisfactory materials for physicochemical solidificationare still not known.

SUMMARY OF THE INVENTION

[0021] Accordingly, an object of the present invention is to providenovel fibrous crystal aggregates usable as an absorbing material foroils satisfying the requirements described above. Another object of thepresent invention is to provide a method of preparing the fibrouscrystal aggregates from a metal carboxylate. A further object of thepresent invention is to provide a method of efficiently recovering oilsflowing into rivers, lakes, marshes or the ocean by physicochemicaladsorption.

[0022] Another object of the present invention is to provide a materialfor solidifying liquid hydrocarbon, which satisfies the requirementsdescribed above. A further object of the present invention is to providea method of preparing the material for solidifying liquid hydrocarbon. Astill further object of the present invention is to provide a method ofsolidifying liquid hydrocarbons efficiently by a physicochemical method.

[0023] Another object of the present invention is to provide asolidifying material which can, in a small amount, solidify wastetempura oils, at room temperature, safely and easily, in easyprocedures. A still other object of the present invention is to providea method of solidifying waste tempura oil easily at ordinarytemperature.

[0024] A further object of the present invention is to provide an edibleoil-solidifying material which can, in a small amount, solidify edibleoil at room temperature to about −20° C., safely and easily, in easyprocedures. A still further object of the present invention is toprovide a method of preparing the edible oil-solidifying material. Astill further object of the present invention is to provide a method ofsolidifying edible oil easily.

[0025] Other and further objects, features, and advantages of theinvention will appear more fully from the following description, takenin connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0026]FIG. 1 is a microphotograph of the fibrous crystal aggregatesobtained in Example 1.

[0027]FIG. 2 is a microphotograph of the fibrous crystal aggregatesobtained in Example 5.

DETAILED DESCRIPTION OF THE INVENTION

[0028] The present inventors have studied the dissolution,emulsification and dispersion behavior, in water, of aliphaticcarboxylic acid type compounds (particularly metal carboxylates) havingalkyl groups of various lengths. As a result, we have found that thesecarboxylic acid type compounds are dissolved completely in water at ahigh temperature; the compounds after completely dissolved can bemaintained in a completely dissolved state even if an aqueous solutionof an inorganic salt, such as sodium chloride, is added thereto at ahigh temperature; by stirring and gradually cooling the compounds in acompletely dissolved state, the carboxylic acid type compounds areprecipitated, for the first time, as aggregates of fine and uniformfibrous crystals; and such fibrous crystal aggregates can particularlyefficiently adsorb and solidify various pure hydrocarbon, mixed oilssuch as gas oil (light oil), oil fuel (heavy oil) and the like, wastetempura oils and edible oils. The present invention is accomplished byfurther studies based on these findings.

[0029] According to the present invention, there are provided thefollowing means:

[0030] (1) A crystal substance, which is formed by precipitating asfibrous aggregates by making a metal aliphatic carboxylate dissolvecompletely in pure water to give a solution, stirring, and graduallycooling the solution;

[0031] (2) A material for recovering oil flowing into rivers, lakes,marshes or the sea, which comprises the fibrous crystal aggregatesaccording to the above (1);

[0032] (3) A crystal substance, which is prepared by precipitating asfibrous aggregates by making a metal aliphatic carboxylate dissolvecompletely in pure water to give a solution, adding an aqueous solutionof an inorganic salt such as sodium chloride containing the same metalas in the metal aliphatic carboxylate, stirring, and gradually coolingthe solution;

[0033] (41) A material for recovering oil flowing into rivers, lakes,marshes or the sea, which comprises the fibrous crystal aggregatesaccording to the above (3);

[0034] (5) A method of recovering flowing oil, which comprises the stepof: solidifying oil flowing into rivers, lakes, marshes or the sea, byusing the recovering material comprising fibrous crystal aggregatesaccording to the above (2) or (4);

[0035] (6) A method of recovering flowing oil, which comprises the stepsof: heating a solidified material containing flowing oil, obtained bythe method according to the above (5), to decompose and separate thesolidified material into its original metal aliphatic carboxylate andflowing oil, and recovering them;

[0036] (7) A method of preparing a fibrous crystal substance, whichcomprises the step of: making a metal aliphatic carboxylate dissolvecompletely in pure water to give a solution, stirring, and graduallycooling the solution, thereby precipitating as fibrous aggregates;

[0037] (8) A method of preparing a fibrous crystal substance, whichcomprises the steps of: making a metal aliphatic carboxylate dissolvecompletely in pure water to give a solution, adding an aqueous solutionof an inorganic salt, such as sodium chloride, containing the same metalas in the metal aliphatic carboxylate, stirring, and gradually coolingthe solution, thereby precipitating as fibrous aggregates;

[0038] (Hereinafter, the means described in the above (1) to. (8), arecollectively referred to as a first embodiment of the presentinvention.)

[0039] (9) A material for solidifying liquid hydrocarbon, whichcomprises fibrous crystal aggregates formed by precipitating by making ametal aliphatic carboxylate dissolve completely in pure water to give asolution, stirring, and gradually cooling the solution;

[0040] (10) A material for solidifying liquid hydrocarbon, whichcomprises fibrous crystal aggregates formed by precipitating by making ametal aliphatic carboxylate dissolve completely in pure water to give asolution, adding an aqueous solution of an inorganic salt, such assodium chloride, containing the same metal as in the metal aliphaticcarboxylate, stirring, and gradually cooling the solution;

[0041] (11) A method of solidifying liquid hydrocarbon, which comprisesthe step of: solidifying liquid hydrocarbon, by using the fibrouscrystal aggregates according to the above (9) or (10);

[0042] (12) A method of solidifying liquid hydrocarbon, which comprisesthe steps of: heating a solidified complex containing solidified liquidhydrocarbon, obtained by the method according to the above (11), todecompose and separate the solidified complex into its original metalaliphatic carboxylate and liquid hydrocarbon, and recovering them;

[0043] (13) A method of preparing a material for solidifying liquidhydrocarbon, which comprises the steps of: making a metal aliphaticcarboxylate dissolve completely in pure water to give a solution,stirring, and gradually cooling the solution, thereby precipitating asfibrous aggregates;

[0044] (14) A method of preparing a material for solidifying liquidhydrocarbon, which comprises the steps of: making a metal aliphaticcarboxylate dissolve completely in pure water to give a solution, addingan aqueous solution of an inorganic salt such as sodium chloridecontaining the same metal as in the metal aliphatic carboxylate,stirring, and gradually cooling the solution, thereby precipitating asfibrous aggregates;

[0045] (Hereinafter, the means described in the above (9) to (14), arecollectively referred to as a second embodiment of the presentinvention.)

[0046] (15) A material for solidifying waste tempura oil, whichcomprises fibrous crystal aggregates formed by precipitating by making ametal aliphatic carboxylate dissolve completely in water to give asolution, stirring, and gradually cooling the solution;

[0047] (16) A material for solidifying waste tempura oil, whichcomprises fibrous crystal aggregates formed by precipitating by making ametal aliphatic carboxylate dissolve completely in water to give asolution, adding an aqueous solution of an inorganic salt such as sodiumchloride containing the same metal as in the metal aliphaticcarboxylate, stirring, and gradually cooling the solution;

[0048] (17) A method of solidifying waste tempura oil, which comprisesthe step of: adding the material for solidifying according to the above(15) or (16) to waste tempura oil, to solidify the waste tempura oil.

[0049] (Hereinafter, the means described in the above (15) to (17), arecollectively referred to as a third embodiment of the presentinvention.)

[0050] (18) A material for solidifying edible oil, which comprisesfibrous crystal aggregates formed by precipitating by making a metalaliphatic carboxylate dissolve completely in pure water to give asolution, stirring, and gradually cooling the solution;

[0051] (19) A material for solidifying edible oil, which comprisesfibrous crystal aggregates formed by precipitating by making a metalaliphatic carboxylate dissolve completely in pure water to give asolution, adding an aqueous solution of an inorganic salt, such assodium chloride, containing the same metal as in the metal aliphaticcarboxylate, stirring, and gradually cooling the solution;

[0052] (20) A method of solidifying edible oil, which comprises the stepof: solidifying edible oil, by using the fibrous crystal aggregatesaccording to the above (18) or (19);

[0053] (21) A method of solidifying edible oil, which comprises the stepof: heating a solidified complex containing solidified edible oil,obtained by the method according to the above (20), to decompose thesolidified complex to regenerate to its original metal aliphaticcarboxylate and edible oil;

[0054] (22) A method of preparing a material for solidifying edible oil,which comprises the steps of: making a metal aliphatic carboxylatedissolve completely in pure water to give a solution, stirring, andgradually cooling the solution, thereby precipitating as fibrousaggregates; and

[0055] (23) A method of preparing a material for solidifying edible oil,which comprises the steps of: making a metal aliphatic carboxylatedissolve completely in pure water to give a solution; adding an aqueoussolution of an inorganic salt, such as sodium chloride, containing thesame metal as in the metal aliphatic carboxylate, stirring, andgradually cooling the solution, thereby precipitating as fibrousaggregates.

[0056] (Hereinafter, the means described in the above (18) to (23), arecollectively referred to as a fourth embodiment of the presentinvention.)

[0057] Hereinafter, the present invention includes the above first,second, third and fourth embodiments, unless otherwise specified.

[0058] The fibrous crystal aggregates of the present invention, as anexample thereof is shown in the drawings in connection with the Examplesdescribed later, are aggregates of innumerable fine fibrous crystals,and the thickness of one fibrous crystal is preferably 1 μm or less, andthe length thereof is preferably 50 to 1000 μm, more preferably 100 to500 μm. Further, one fibrous crystal is composed of a large number offiner fibrous crystals.

[0059] In the present invention, the crystals comprising fibrousaggregates to be solidified upon adsorption of flowing oils in the firstembodiment, the crystals comprising fibrous aggregates acting as amaterial for solidifying liquid hydrocarbon in the second embodiment,the crystals comprising fibrous aggregates acting as a material forsolidifying waste tempura oil in the third embodiment, and the crystalscomprising fibrous aggregates acting as a material for solidifyingedible oil in the fourth embodiment are formed by heating and dissolvinga metal aliphatic carboxylate in pure water or water, or dissolving ametal aliphatic carboxylate in pure water or water and then adding anaqueous solution of an inorganic salt (such as a sodium salt (e.g.,sodium chloride, sodium sulfate, sodium carbonate and the like), apotassium salt (e.g., potassium chloride and the like) a lithium salt(e.g., lithium chloride and the like) and the like containing the samemetal as in the metal aliphatic carboxylate, followed by stirring andgradual cooling thereof. The fibrous crystal aggregates are maintainedstably in the form of a dispersion of the fibrous crystal aggregates fora long period usually at room temperature or lower.

[0060] As used herein, the liquid hydrocarbon refers to that in the formof liquid at ordinary temperature (20° C.) at normal pressure (0.1 MPa).

[0061] As used herein, the waste tempura oil refers not to edible oilitself, but to used tempura oil including oil discolored by oxidation inthe air, or partially degraded, after heated and used, and oil slightlydarkened, or having increased viscosity through repeated use, and thelike. The waste tempura oil may be composed of 100% waste tempura oil orof waste tempura oil mixed with water, egg yellow, wheat flour and thelike.

[0062] In the present invention, solidification means that flowing oils,liquid hydrocarbon, waste tempura oil or edible oil is solidified byforming a complex with the fibrous crystal aggregates.

[0063] The metal aliphatic carboxylate (also referred to, in the presentinvention, as metal carboxylate) used in the present invention is ametal carboxylate preferably having a linear alkyl chain. The number ofcarbon atoms in the metal carboxylate is preferably 6 to 30, morepreferably 8 to 22 and most preferably 10 to 18. A kind of the metalthereof is preferably sodium, potassium or lithium, more preferablysodium or potassium. That is, the alkyl chain should have such suitablelength that the metal carboxylate is completely dissolved in pure wateror water by heating, and then stirred and gradually cooled as it is orafter addition of an aqueous solution of an inorganic salt such assodium chloride and the like containing the same metal as in the metalaliphatic carboxylate, whereby the metal carboxylate can be precipitatedin a fibrous form.

[0064] In the case of a sodium carboxylate having a linear alkyl groupwhere the number of carbon atoms is 6 to 10, it may be necessary toincrease the concentration of sodium chloride or hydrated sodium sulfateor to cool the compound at room temperature or less. When the number ofcarbon atoms is 19 or more, it is necessary to heat the compound at 100°C. or more or to decrease the concentration of sodium chloride, in orderto dissolve the compound completely.

[0065] This also applies to a potassium or lithium carboxylate having aliner alkyl group.

[0066] The examples of the metal carboxylate which can be used in thepresent invention include, for example, sodium octanoate, sodiumnonanoate, sodium decanoate, sodium undecanoate, sodium dodecanoate,sodium tridecanoate, sodium tetradecanoate, sodium pentadecanoate,sodium hexadecanoate, sodium heptadecanoate, sodium octadecanoate,potassium tetradecanoate, potassium hexadecanoate, potassiumoctadecanoate, lithium hexadecanoate and the like.

[0067] Sodium aliphatic carboxylates have been used as soap for a longtime, and their safety is proven. Potassium aliphatic carboxylates havealso been used widely as medicated soap, and their safety is alsoproven. Further, lithium aliphatic carboxylates have also beenindustrially used, and their safety is confirmed. Further, sodium andpotassium are contained originally in the environmental water includingseawater in large quantities, and even if they flow and remain in thesea, the environment is not adversely affected. Further, sodium andpotassium are also contained at various concentrations in rivers, lakesand marshes, and even if they flow and remain at a concentration ofextent included already there, the environment is not adverselyaffected.

[0068] The aqueous solution of sodium chloride used in the presentinvention is produced by dissolving various amounts of sodium chloridein pure water or water. The aqueous solution is generally effective atconcentrations ranging from a low concentration where sodium is slightlydissolved in water to the upper limit of the solubility thereof, but itis essential that depending on combination with the metal carboxylate,the concentration of the aqueous solution be high enough for crystals tobe precipitated as fibrous aggregates, and the precipitated fibrouscrystal aggregates be solidified effectively, depending on its use, byreacting with flowing oil in the first embodiment, liquid hydrocarbon inthe second embodiment, waste tempura oil in the third embodiment oredible oil in the fourth embodiment. Further, sodium chloride is notalways necessary to be pure, but sodium chloride may be present as aconstituent component of seawater or natural water, be nontoxic tohumans and other living things and be dissolved at a concentration wherethe dissolved carboxylate can be precipitated. Further, seawater itselfor artificial seawater may be used as it is. However, in the fourthembodiment, in consideration that sodium chloride used in the materialfor solidifying edible oil is added to foods, it is preferable thatsodium chloride is used at high purity or usual levels in foods, ornatural water confirmed to be safe or natural water of known taste asdrinking water is used. This also applies to other inorganic metalsalts.

[0069] In the method of preparing the fibrous crystal aggregates and thesolidifying material according to the present invention, it isparticularly important that first the metal carboxylate described aboveis completely dissolved in pure water or water, and if necessary anaqueous solution containing metal ions is added thereto and completelymixed therewith, followed by stirring and gradual cooling thereof,whereby crystals are precipitated as fibrous aggregates in the aqueoussolution.

[0070] By use of the crystals as fibrous aggregates, it becomes possibleto adsorb flowing oils, liquid hydrocarbon, waste tempura oil and edibleoil efficiently, and thereby to recover the oils as macroscopic mass. Itis considered this occurs because the crystals as fibrous carboxylateaggregates of metal carboxylate have a large surface area to permitflowing oil, liquid hydrocarbon, waste tempura oil or edible oil to beefficiently adsorbed therein, and the resultant oil-adsorbed materialsare attracted to one another via van der Waals force, to grow finally assolid materials which can be recovered easily even by e.g. a net orhand.

[0071] In the case of edible oils, the recovered product can beconverted into new solid foods.

[0072] In the process of the present invention, the embodiments forpreparing the material for adsorbing flowing oils in the firstembodiment, the material for solidifying liquid hydrocarbon in thesecond embodiment, the material for solidifying waste tempura oil in thethird embodiment, and the material for solidifying edible oil in thefourth embodiment, each of which is comprised of the fibrous crystalaggregates, are as follows:

[0073] (1) A process wherein a metal carboxylate is added to pure wateror water, completely dissolved by heating, and then the mixture iscooled gradually to room temperature under vigorous stirring;

[0074] (2) A process wherein a metal carboxylate is added to pure wateror water and completely dissolved by heating, and after a previously,heated aqueous solution of sodium chloride is added thereto, the mixtureis cooled gradually to room temperature under vigorous stirring;

[0075] (3) A process wherein an aqueous solution of various metal salts(an aqueous solution of metal salts nontoxic to the human body),seawater or artificial seawater is used in place of the aqueous solutionof sodium chloride in the process (2); and

[0076] (4) A process wherein after the solution is cooled to roomtemperature in the process (2) or (3), the solution is further kept atabout 0° C. for a long time, to precipitate crystals consisting offibrous aggregates.

[0077] Further, there is (5) a process wherein crystals of mixed fibrousaggregates of plural types of carboxylates are precipitated by using theprocesses (1) to (4).

[0078] The molar ratio of metal carboxylate/water in precipitating thefibrous crystal aggregates in the present invention is preferably from0.1/1000 to 10/1000, more preferably from 0.5/1000 to 2/1000. Further,the molar ratio of inorganic metal salt/water in precipitating thefibrous crystal aggregates is preferably from 0/1000 to the saturationconcentration during heating.

[0079] Furthermore, the embodiment is described in more detail. First,heating is carried out in the present invention in order to dissolve thecarboxylate completely in pure water or water. The heating temperatureis varied depending on the type of metal carboxylate used. For example,sodium carboxylates ranging from sodium pentadecanoate to octadecanoateare heated at 90 to 99° C. for about 30 minutes. Carboxylates having ashorter chain may be heated at lower temperatures. Carboxylates having alonger chain should be heated at a high temperature of 100° C. or morein a pressure-resistant vessel in some cases. In either case, after themetal carboxylate is completely dissolved by heating, the resultingsolution is vigorously stirred; or after a heated aqueous solution ofsodium chloride or an aqueous solution of various metal salts is added,the mixture is vigorously stirred vigorous stirring is continued untilthe temperature of the solution is lowered to room temperature.

[0080] In the manner described above, very fine and fibrous crystalaggregates can be precipitated.

[0081] The fibrous crystal aggregates thus formed can be separated fromthe seawater, the aqueous solution and the like by a usual means such ascentrifugation and the like or scooping the fibrous crystal aggregatesup from the aqueous solution of metal salts, but usually the fibrouscrystal aggregates are used with the condition which dispersed in water.In this case, the water content is not limited, but is preferably 80 to99% by weight in the hydrous fibrous crystal aggregates. Accordingly,the water content may be lowered just before use. Once formed, thefibrous crystal aggregates are very stable and usually maintained stablyeven at room temperature for a long time or even at high temperatures.For example, fibrous crystal aggregates obtained from sodiumpentadecanoate are very stable usually at a temperature of up to 60° C.

[0082] In the first embodiment of the invention, the fibrous crystalaggregates formed by the process of the present invention describedabove are merely introduced into e.g. seawater polluted with oil fuelthereby selectively adsorbing the oil fuel. Unless the ratio of oil fuelto the fibrous crystal aggregates is too high, the fibrous crystalaggregates adsorb all oil fuel substantially to float on the cleanedseawater. The fibrous crystal aggregates after having adsorbed oil fuelin a lower ratio of the oil fuel float on the sea as fine particleaggregates, but when the ratio of oil fuel by weight is higher byseveral times than the fibrous crystal aggregates, the aggregates floaton the sea as wholly rigid and strong spherical mass (or egg-shapedmass). The mass is maintained in a solid form and can be separated fromthe seawater by scooping it up with a usual means using a net, a rakeand the like.

[0083] The flowing oils or liquid hydrocarbon which can be adsorbed andrecovered by the recovering material consisting of the fibrous crystalaggregate of the present invention in the first and second embodimentsinclude mixed oil such as oil fuel A, oil fuel C, crude oil, liquidparaffin, gas oil, kerosene and the like, and a wide variety of purifiedhydrocarbon, that is, aliphatic or aromatic hydrocarbons such asn-paraffins, olefins, branched paraffins, cyclohexane and the like.Depending on the type of flowing oils or liquid hydrocarbon to berecovered, generally 10 to 70 g, preferably 10 to 30 g of flowing oilsor liquid hydrocarbon can be adsorbed by 1 g of the fibrous crystalaggregates of the present invention. To allow the fibrous crystalaggregates of the present invention to adsorb flowing oils or liquidhydrocarbon, the fibrous crystal aggregates may be contacted withflowing oils or liquid hydrocarbon preferably for 1 minute or more, morepreferably with gentle shaking.

[0084] If the oil adsorbed is not a mixed oil, such as oil fuel and thelike, hardly separated, the solids (solid aggregates) which haveadsorbed the flowing oils or liquid hydrocarbon can be separated intothe respective components i.e. the metal carboxylate and recovered oilsor liquid hydrocarbon by mere heating or by heating after separation andrecovery from the flowing water and subsequent addition of water. Themetal carboxylate is separated and transferred to the aqueous phase,while the oils or liquid hydrocarbon can be separated and recovered fromthe aqueous phase. A majority of the metal carboxylates can be usedagain and repeatedly for producing of fibrous crystal aggregates usableas the adsorbing material for flowing oils or liquid hydrocarbon.Usually, heating for decomposition and separation is conductedpreferably at 80° C. or more. According to the solidifying material inthe second embodiment of the present invention, liquid hydrocarbon canbe adsorbed at room temperature.

[0085] In the third and fourth embodiments, the fibrous crystalaggregates formed by the process of the present invention as describedabove are merely introduced into waste tempura oil or edible oil atordinary temperature thereby selectively adsorbing the waste oil oredible oil. Unless the ratio of waste tempura oil or edible oil to thefibrous crystal aggregates is too high, the fibrous crystal aggregatesadsorb all tempura oil or edible oil substantially to form ball-shapedsolids, thus floating on water mixed therewith. If the solidifiedcomplex thus formed is used as a food made of solidified edible oil,other oil-soluble foods, food additives and the like may be addeddepending on the intended use of the solidified food. The solid ismaintained in a solid form and can be scooped up by hand or a usualmeans such as a dipper.

[0086] The waste tempura oil or edible oil which can be solidified bythe solidifying material in the third and fourth embodiments of thepresent invention includes soybean oil, cottonseed salad oil, rapeseedoil, corn oil, safflower salad oil, palm oil, sunflower oil, rice oil,sesame oil, olive oil and the like. Depending on the type of wastetempura oil or edible oil to be solidified, 10 to 50 g, preferably 10 to30 g waste tempura oil or edible oil can be adsorbed usually by 1 g ofthe solidifying material in the third and fourth embodiments of thepresent invention. To allow the solidifying material in the thirdembodiment of the present invention to adsorb waste tempura oil, thesolidifying material consisting of fibrous crystal aggregates may becontacted with waste tempura oil preferably for 0.1 minute or more atroom temperature, more preferably with gentle shaking or stirring. Onthe other hand, to allow the solidifying material in the fourthembodiment of the present invention to adsorb edible oil, thesolidifying material may be contacted with edible oil preferably for 1minute or more in the range of room temperature to −20° C., morepreferably with gentle shaking or stirring.

[0087] The solidified complex formed after solidification of the edibleoils can be separated into the respective components i.e. the metalcarboxylate and solidified edible oils by gently heating the complex ata temperature not causing a deterioration in the properties and flavorof the original edible oil. The metal carboxylate is separated andtransferred to the aqueous phase, while the edible oils can be separatedfrom the aqueous phase and returned to the original edible oil. Further,a majority of the metal carboxylates can be used again and repeatedlyfor producing fibrous crystal aggregates usable as the material forsolidifying edible oil. Usually, heating for decomposition andseparation is conducted at 80° C. or less.

[0088] The fibrous crystal aggregates of the present invention obtainedby dispersing a metal aliphatic carboxylate in an aqueous solution of ametal salt can be used as a material for adsorbing oils, a material forsolidifying liquid hydrocarbon, a material for solidifying waste tempuraoil, a material for solidifying edible oil, and the like.

[0089] According to the first embodiment of the present invention,flowing oils allowed to contact therewith in rivers, lakes, marshes orthe ocean can be adsorbed selectively, efficiently andphysicochemically. Further, according to the second embodiment of thepresent invention, liquid hydrocarbon can be adsorbed selectively,efficiently and physicochemically. The recovering material on theliquid-hydrocarbon solidifying material comprising the fibrous crystalaggregates of the present invention is maintained in a solid form(usually in a ball- or egg-shaped form) by adsorption of flowing oils orliquid hydrocarbon to float on the water, so after adsorption, thematerial can be easily recovered from the water or seawater. Thisadsorbing or solidifying material is composed of only a very safe metalaliphatic carboxylate and an aqueous solution of a metal salt.Accordingly, even if flowing out, environmental pollution of naturalwater and the like caused by the adsorbing or solidifying materialitself can also be prevented Further, the fibrous crystal aggregates ofthe present invention and the material for recovering flowing oil or thematerial for solidifying liquid hydrocarbon comprising the same can beeasily handled because it can be kept stably for a long period of timein the form of a dispersion of the fibrous crystal aggregates in waterat room temperature. When these materials are allowed to adsorb oilsother than oil fuel, they can be separated by heating into the metalcarboxylate and recovered oils or solidified liquid hydrocarbon, and theflowing oil and liquid hydrocarbon can be recovered in the originalstate, further the metal carboxylate can be reutilized for production ofthe fibrous crystal aggregates and the material for recovering flowingoil or the material for solidifying liquid hydrocarbon comprising thesame.

[0090] The method of recovering flowing oils by using such fibrouscrystal aggregates in the first embodiment of the present invention issuitable for handling of flowing-oil accidents. Further the method ofsolidifying liquid hydrocarbon by using such fibrous crystal aggregatesin the second embodiment of the present invention can be carried outeffectively and easily by utilizing physiochemical adsorption, which issuitable as a method of transporting liquid hydrocarbon or handling forstorage thereof.

[0091] Further, the solidifying material consisting of the fibrouscrystal aggregates in the third embodiment of the present invention canbe maintained in a solid state by adsorption of waste tempura oil anddischarged easily and safely as it is without polluting the environment.Accordingly, pollution of the natural environment can also be prevented.Waste tempura oil thus solidified can also be reutilized by conversioninto soap and the like. Further, the solidifying material consisting ofthe fibrous crystal aggregates of the present invention can bemaintained stably for a long period of time in the form of a dispersionof the fibrous crystal aggregates at room temperature, thus permittingit to be handled easily and stored safely for a long period.

[0092] The method of solidifying waste tempura oil according to thepresent invention by using the solidifying material consisting of suchfibrous crystal aggregates is suitable for handling of waste oil fromhome, waste oil from food factories, waste oil discharged from cookroomsin restaurants and the like.

[0093] Further, the material for solidifying edible oil consisting ofthe fibrous crystal aggregates obtained by dispersing a metal aliphaticcarboxylate in an aqueous solution of a metal salt in the fourthembodiment of the present invention can be maintained in a solid state(usually in a ball or egg form) by adsorption of edible oil, and cansolidify the edible oil easily and safely, to convert it into new foods.Further, the material for solidifying edible oil consisting of thefibrous crystal aggregates of the present invention can be maintainedstably for a long period of time in the form of a dispersion of thefibrous crystal aggregates at room temperature, thus permitting it to behandled easily and stored safely for a long period. Further, it ispossible to separate into the metal carboxylate and solidified edibleoil by heating, so the edible oil can be returned in the original state,while the metal carboxylate can be reutilized for production of thematerial for solidifying edible oil consisting of the fibrous crystalaggregates.

[0094] The method of solidifying edible oil according to the presentinvention by using such fibrous crystal aggregates can solidify edibleoil harmlessly and safely without a deterioration in the properties ofthe edible oil, so this method is suitable hot only as a method ofhandling for storage and transportation but also as a method ofproducing of a new oily solid food.

[0095] The present invention will be described in more detail based onexamples given below, but the present invention is not limited by theseexamples.

EXAMPLES Example 1

[0096] 132 mg (0.0005 mole) sodium pentadecanoate in a high purity (99%or more) and 4.5 ml (0.25 mole) pure water were weighed and placed in aglass vessel, sealed and heated at 95° C., whereby the sodiumpentadecanoate was completely dissolved. Separately, an aqueous solutionprepared by completely dissolving 58.5 mg (0.010 mole) sodium chloridein 4.5 ml (0.25 mole) pure water was heated at 95° C. Both the solutionswere mixed at 95° C., and immediately the mixture was vigorouslystirred. The mixture was stirred for about 20 minutes until the mixturewas cooled to room temperature, whereby very fine and uniform fibrouscrystal aggregates were precipitated throughout the solution. By leavingit at room temperature for 1 day, the fibrous crystal aggregates weremade more stable and tried to gather on the water by attraction of theaggregates to one another maintaining the form of fine crystals, thusmade the aqueous solution slightly colorless and transparent in a lowerpart. A microphotograph of the fibrous crystal aggregates of sodiumpentadecanoate thus prepared is shown in FIG. 1 (×40).

[0097] 1.5 g oil fuel C was added to the liquid in which the fibrouscrystal aggregates were dispersed and gently shaken, whereby the oilfuel was dispersed as fine black droplets throughout the white liquid inwhich the fibrous crystal aggregates were dispersed, and then thefibrous crystal aggregates of the sodium pentadecanoate and the finedroplets of the oil fuel started mutually to aggregate to form hugerigid ball-shaped aggregates (solids) as a whole. The remaining aqueoussolution of sodium chloride was free of sodium pentadecanoate and oilfuel and completely colorless and transparent. Further, the huge rigidball-shaped solids contained little water.

Example 2

[0098] The same procedure as in Example 1 was conducted except that 139mg (0.0005 mole) sodium hexadecanoate was used in place of sodiumpentadecanoate, and as a result, very fine and uniform fibrous crystalaggregates were precipitated completely similarly throughout thesolution. 1.5 g oil fuel C was added thereto, and the mixture was gentlyshaken, to form stable and rigid ball-shaped solids, and the separatedaqueous solution of sodium chloride was also colorless and transparent.

Example 3

[0099] The same procedure as in Example 1 was conducted except that purewater or seawater was used in place of the aqueous solution of sodiumchloride, and as a result, the same result was obtained until thequantity of addition of oil fuel C was from 10 to 70 times in weightratio.

Example 4

[0100] The same procedure as in Example 1 was conducted except that0.0005 mole of sodium undecanoate, sodium dodecanoate, sodiumtridecanoate, sodium tetradecanoate, sodium heptadecanoate or sodiumoctadecanoate was used respectively in place of sodium pentadecanoate,and as a result, rigid and stable ball-shaped solids were obtained untiloil fuel C was. 15.3, 13.5, 9.2, 10.2, 11.5 and 11.2 times in weightratio respectively, to float on each colorless and transparent aqueoussolution of sodium chloride.

Example 5

[0101] The same procedure as in Example 1 was conducted except that0.0005 mole of sodium decanoate was used in place of sodiumpentadecanoate, and as a result, no fibrous crystal aggregates wereprecipitated even after an aqueous solution of sodium chloride was addedthereto, stirred and left at room temperature. Accordingly, the mixturewas further kept at 4° C. for one day, and as a result, similar fibrouscrystal aggregates were precipitated, and the aggregates thusprecipitated were stable for a long time even at room temperature. Amicrophotograph (×100) of the fibrous crystal aggregates of sodiumpentadecanoate thus prepared is shown in FIG. 2. Similarly to Example 1,oil fuel C was added to the liquid in which the fibrous crystalaggregates were dispersed, and as a result, rigid solids could beobtained until the quantity of addition of oil fuel C to sodiumcaboxylate was 15.0 times in weight ratio.

Example 6

[0102] The same procedure as in Example 1, 3 or 4 was conducted exceptthat n-Pentane, n-hexane, n-heptane, n-octane, benzene, toluene,o-xylene, 2,2,4-trimethyl pentane, 1-decene, cyclohexane, oil fuel A,liquid paraffin, gas oil or kerosene was used respectively in place ofoil fuel C, and as a result, very rigid ball-shaped solids could beobtained until the ratio thereof to sodium pentadecanoate was from 15 to70 times in weight ratio respectively. The remaining pure water oraqueous solution remained colorless and transparent or slightly opaque.By heating the solidified material at 60 to 90° C., the original oilcomponent could be easily recovered.

Example 7

[0103] 10 g sodium pentadecanoate in a high purity (99% or more) and 400g water were weighed and placed in a glass vessel, sealed and heated at95° C., whereby the sodium pentadecanoate was completely dissolved.Separately, an aqueous solution prepared by completely dissolving 5 gsodium chloride in 400 g water was heated at 95° C. Both the solutionswere mixed at 95° C., and immediately the mixture was vigorouslystirred. The mixture was stirred for about 20 minutes until the mixturewas cooled to room temperature, whereby very fine and uniform fibrouscrystal aggregates were precipitated throughout the solution. By leavingit at room temperature for 1 day, the fibrous crystal aggregates weremade more stable and tried to gather on the water by attraction of theaggregates to one another in the form of fine crystals, thus made theaqueous solution slightly colorless and transparent in a lower part. Amicrophotograph (×40) of the fibrous crystal aggregates of sodiumpentadecanoate thus prepared was the same as in FIG. 1.

[0104] 150 g waste cottonseed salad oil was added to the liquid in whichthe fibrous crystal aggregates were dispersed (content of the fibrouscrystal aggregates was 1.3% by weight, the balance being water) andgently stirred, whereby the fibrous crystal aggregates of sodiumpentadecanoate and fine droplets of the waste oil started mutually toaggregate to form huge rigid and slightly yellowish ball-shapedaggregates as a whole. The remaining aqueous solution was free of sodiumpentadecanoate and waste oil and completely colorless and transparent.Further, the huge rigid ball-shaped complexes contained little water.When additional waste oil was added, the oil was adsorbed completely bythe ball-shaped complexes.

Example 8

[0105] The same procedure as in Example 7 was conducted except that 9 to12 g sodium undecanoate, sodium dodecanoate, sodium tridecanoate, sodiumtetradecanoate, sodium heptadecanoate or sodium octadecanoate was usedrespectively in place of sodium pentadecanoate in Example 7, and as aresult, rigid stable macroscopic ball-shaped complexes were obtaineduntil the ratio of waste cottonseed salad oil to each of sodiumcarboxylates was 20, 25, 25, 20, 30 and 30 times in weight ratiorespectively, to float on each colorless and transparent aqueoussolution of sodium chloride.

Example 9

[0106] The same procedure as in Example 7 was conducted except thatsoybean oil, rapeseed oil, corn oil, safflower salad oil, palm oil, riceoil, sesame oil or olive oil, each of which was waste oil, was usedrespectively in place of waste cottonseed salad oil in Example 7, and asa result, very rigid macroscopic ball-shaped complexes were obtaineduntil the ratio thereof to fibrous crystal aggregate was 10 to 50 timesin weight ratio. The remaining aqueous water or aqueous solutionremained colorless and transparent or slightly opaque.

Example 10

[0107] The same procedure as in Example 7 was conducted except that purewater was used in place of water in Example 7, and as a result, fibrouscrystal aggregates were obtained. A microphotograph (×40) of the fibrouscrystal aggregates of sodium pentadecanoate thus prepared was the sameas in FIG. 1.

[0108] 150 g cottonseed salad oil was added to the liquid in which thefibrous crystal aggregates were dispersed and gently stirred, wherebythe fibrous crystal aggregates of sodium pentadecanoate and finedroplets of the cottonseed salad oil started mutually to aggregate, toform huge rigid and slightly yellowish ball-shaped aggregates(solidified materials) as a whole. The remaining aqueous solution ofsodium chloride was free of sodium pentadecanoate and cottonseed saladoil and completely colorless and transparent. Further, the huge rigidball-shaped solidified materials contained little water.

Example 11

[0109] The same procedure as in Example 7 was conducted except thatcottonseed salad oil, soybean oil, rapeseed oil, corn oil, safflowersalad oil, palm oil, sunflower oil, rice oil, sesame oil or olive oil,which were edible oil, was used oil respectively in place of wastecottonseed salad oil in Example 7, and as a result, very rigidball-shaped solidified materials could be formed until the ratio thereofto fibrous crystal aggregate was from 10 to 50 times in weight ratio.The remaining pure water or aqueous solution remained colorless andtransparent or slightly opaque. The solidified materials could be easilyreturned to the original edible oil by heating at 60 to 80° C.

[0110] Having described our invention as related to the presentembodiments, it is our intention that the invention not be limited byany of the details of the description, unless otherwise specified, butrather be construed broadly within its spirit and scope as set out inthe accompanying claims.

What is claimed is:
 1. A crystal substance, which is formed byprecipitating as fibrous aggregates by making a metal aliphaticcarboxylate dissolve completely in pure water to give a solution,stirring, and gradually cooling the solution.
 2. A material forrecovering oil flowing into rivers, lakes, marshes or the sea, whichcomprises the fibrous crystal aggregates according to claim
 1. 3. Acrystal substance, which is prepared by precipitating as fibrousaggregates by making a metal aliphatic carboxylate dissolve completelyin pure water to give a solution, adding an aqueous solution of aninorganic salt containing the same metal as in the metal aliphaticcarboxylate, stirring, and gradually cooling the solution.
 4. A materialfor recovering oil flowing into rivers, lakes, marshes or the sea, whichcomprises the fibrous crystal aggregates according to claim
 3. 5. Amethod of preparing a fibrous crystal substance, which comprises thesteps of: making a metal aliphatic carboxylate dissolve completely inpure water to give a solution; stirring; and gradually cooling thesolution, thereby precipitating as fibrous aggregates.
 6. A method ofpreparing a fibrous crystal substance, which comprises the steps of:making a metal aliphatic carboxylate dissolve completely in pure waterto give a solution; adding an aqueous solution of an inorganic saltcontaining the same metal as in the metal aliphatic carboxylate;stirring; and gradually cooling the solution, thereby precipitating asfibrous aggregates.
 7. A method of solidifying waste tempura oil, whichcomprises the step of: adding the fibrous crystal aggregates accordingto claim 1 to waste tempura oil, to solidify the waste tempura oil.
 8. Amethod of solidifying waste tempura oil, which comprises the step of:adding the fibrous crystal aggregates according to claim 3 to wastetempura oil, to solidify the waste tempura oil.
 9. a method ofsolidifying edible oil, which comprises the step of: solidifying edibleoil, by using the fibrous crystal aggregates according to claim
 1. 10. Amethod of solidifying edible oil, which comprises the step of: heating asolidified complex containing solidified edible oil, obtained by themethod according to claim 9, to decompose the solidified complex toregenerate to its original metal aliphatic carboxylate and edible oil.11. A method of solidifying edible oil, which comprises the step of:solidifying edible oil, by using the fibrous crystal aggregatesaccording to claim
 3. 12. A method of solidifying edible oil, whichcomprises the step of: heating a solidified complex containingsolidified edible oil, obtained by the method according to claim 11, todecompose the solidified complex to regenerate to its original metalaliphatic carboxylate and edible oil.